1. Field of Invention
This invention relates to semiconductor light emitting devices wherein a small portion of light emitted from the device is converted by a wavelength converted material.
2. Description of Related Art
The luminous efficiency of a light source is expressed in lumens per watt and is a measure of how efficiently the light source converts electrical power to luminous flux or brightness. For a given brightness, a device with high luminous efficiency requires less electrical power than a device with lower luminous efficiency. Thus, a device with high luminous efficiency may be less expensive to operate at a given brightness than a device with lower luminous efficiency.